T2 display has better contrast, higher reflectivity and warm white color. T1 screen gives colour what is perceived as "gray".
If this is the result of changes in technology, "the ink", or the transmission spectrum of the glass, it does not matter. There is a fact, and this is important.

The improvement of the power supply circuit screen (and perhaps the best of its software configuration) gives a significant effect to reduce the visibility of artifacts: the T1 (left) screen and the T2 on the right with the same book...